# Synth

> Synth Index searches reviewed, versioned research Contributions with exact citations. Access is through the `synth-ai` Python SDK, CLI, HTTP and hosted MCP.

## Start

- SDK: `pip install synth-ai==0.23.1` (wheel sha256 6f7d85b67888142bc45cab322c1cdbf2eeee1ba03ed6d60e30e79dc3cf4486e7)
- [Hosted MCP server](https://api.usesynth.ai/mcp)
- [Synth agent skill](https://docs.usesynth.ai/skills/synth/SKILL.md)
- [Python SDK (synth-ai on PyPI)](https://pypi.org/project/synth-ai/)
- [Get started](https://docs.usesynth.ai/sdk/overview)
- [Index quickstart](https://docs.usesynth.ai/synth-index/quickstart)
- [MCP reference](https://docs.usesynth.ai/reference/mcp)
- [SDK reference](https://docs.usesynth.ai/reference/sdk)
- [CLI reference](https://docs.usesynth.ai/reference/cli)
- [Index pricing and limits](https://docs.usesynth.ai/synth-index/private-search)
- [Docs index for agents (llms.txt)](https://docs.usesynth.ai/llms.txt)

## Site

- [Home](https://www.usesynth.ai/)
- [For agents](https://www.usesynth.ai/agents)
- [Docs](https://docs.usesynth.ai)

## Research

- [Scaling Train Time Compute for Gepa](https://www.usesynth.ai/research/scaling-train-time-compute-for-gepa): Scaling train-time compute for GEPA across public task containers — same-container comparisons, coverage curves, and proposer scaling evidence.

## Release notes

- [Synth v0.23: Index Search from the SDK and MCP, and weekly included usage](https://www.usesynth.ai/changelog/2026-10-16-synth-v023): Search cited research with FAST Search from the Python SDK, HTTP or hosted MCP, and start on a Free plan with $10 of usage every week.